Signalflåter

Signalflåter refers to a historical maritime signaling concept described in some Nordic maritime sources. The term combines signal with flåter (plural of raft), and denotes a system in which a line of signaling rafts or buoys was deployed along a coastline or river to convey information visually between ships and shore.

In practice, signalflåter involved rafts equipped with signaling devices such as semaphore arms, colored flags, lanterns, or reflective surfaces. Messages were transmitted by the arrangement, orientation, or sequence of signals across relatively short distances, relying on line-of-sight communication. The network functioned as a practical means to relay weather advisories, navigational instructions, or harbor entries without the need for runners or single fixed beacons.

Historical usage of signalflåter is chiefly documented in older maritime records and port administrations of the Nordic region, with references appearing from the early modern period through the 19th century. Implementations varied by locality, and signal rafts were typically integrated into broader signaling systems that included beacons, flag lines, and watch stations. The rise of faster telegraph services, improved lighthouse networks, and eventually wireless communication led to the decline of raft-based signaling in most areas by the late 19th to early 20th century.

Today, mentions of signalflåter appear mainly in historical analyses, museum exhibits, and heritage projects that aim to preserve and understand traditional maritime signaling practices. See also semaphore signaling, navigator’s beacons, and coastal communication systems.